E. coli Sepsis: Red Flag for Colon Carcinoma-A Case Report and Review of the Literature

A Diagnostic Quandary of Escherichia Coli Pneumonia: A Case Report and Literature Review

Escherichia coli community-acquired pneumonia (CAP) is an under-recognized condition associated with higher mortality compared to the other well-studied causes of pneumonia. E. coli pneumonia is frequently associated with bacteremia. Despite the absence of abdominal or urinary symptoms, the infection may originate from an occult gastrointestinal (GI) source since it is a common commensal bacteria of the GI tract. Conditions related to extraintestinal pathogenic E. coli (ExPEC) are gaining attention, and there has been a trend toward the rise of pneumonia secondary to gram-negative bacteria. This presents a diagnostic stewardship dilemma in a patient with sepsis, E. coli bacteremia, and apparent pneumonia - to assume and treat for E. coli CAP or to look for a GI/genitourinary source which may, in turn, lead to incidental findings and further studies. We report a case of E. coli CAP in a 62-year-old patient and our approach regarding the treatment and imaging course.

Synthesis and evaluation of novel naphthol diazenyl scaffold based Schiff bases as potential antimicrobial and cytotoxic agents against human colorectal carcinoma cell line (HT-29)

BACKGROUND

In search of new antimicrobial and cytotoxic agents, a series of new naphthol diazenyl scaffold based Schiff bases (NS1-NS23) was efficiently synthesized by condensation of 2-hydroxy naphthaldehyde azo dyes with various substituted aromatic/heteroaromatic/aliphatic amines.

METHODOLOGY

The synthesized derivatives were characterized by various physicochemical and spectral techniques and assessed for in vitro antimicrobial and cytotoxic potential against human colorectal carcinoma cell line (HT-29). The active derivatives were further evaluated for their apoptotic potential by Annexin-V/propidium iodide double staining assay using flow cytometer and analyzed for cell-cycle arrest studies.

RESULTS AND CONCLUSION

The derivative NS-2 was found maximum active against E. coli, S. enterica and B. subtilis. The derivatives NS-12, NS-15, NS-21, and NS-23 showed maximum antifungal activity against A. fumigatus. The maximum cytotoxicity was observed from the derivatives NS-2, NS-8, NS-21, and NS-23 towards HT-29 cell line with IC50 between 4 and 19 μg/ml. More than 90% and 62% of the cells were found in the apoptotic phase on treatment with NS-2 and NS-21 respectively in comparison to the 68% for doxorubicin. Further, these derivatives arrested the cell growth in S and G2/M phase of the cell cycle.

Oral supplementation with lactobacilli to prevent colorectal cancer in preclinical models

Colorectal cancer (CRC) is still a major threat for public health, as it is the third most common cancer in men and the second in women and it ranks second among tumors in terms of mortality. Evidence from the last decades emphasizes the complex role of gut microbial composition in CRC development. Historically, it is believed that dairy products, a source of lactobacilli and other lactic acid bacteria, are beneficial for human health and help in preventing CRC. We searched online literature for trials evaluating the preventive role of lactobacilli in CRC animal models. Most of selected studied assessed a relevant role of lactobacilli in preventing CRC and precursor lesions. Mechanisms through which this effect was achieved are supposed to regard immunomodulation, regulation of apoptosis, gut microbial modulation, genes expression, reduction of oxidative stress and others. Lactobacilli oral supplementation is reported to be effective in preventing CRC in animal models, even if the underlying mechanisms of action are still not fully understood.

Escherichia coli bloodstream infection preceding the diagnosis of rectal carcinoma

Background:

Cancer is one of the major comorbidities in patients with sepsis, and conversely, bloodstream infections (BSI) may precede the diagnosis of colorectal malignancy, in particular when Streptococcus gallolyticus is isolated. We present the rare case of an Escherichia coli BSI preceding the diagnosis of rectal adenocarcinoma.

Case presentation:

A 56-year-old man with a history of ocular myasthenia gravis presented with fever and shaking chills, and was diagnosed with E. coli BSI of unknown origin. After a thorough history and examination, diagnostic workup revealed a rectal adenocarcinoma as portal of entry for E. coli BSI. The choice of definitive antibiotic treatment was complicated by the risk of myasthenia gravis exacerbation by several classes of antibiotics.

Conclusions:

In patients with E. coli BSI of unknown origin, clinicians need a high index of suspicion regarding underlying colorectal malignancies. This may permit earlier diagnosis in a potentially curable stage.

CD8+ T Cells Prevent Lethality from Neonatal Murine Roseolovirus Infection

A recently described mouse homolog of the human roseoloviruses, murine roseolovirus (MRV), causes loss of peripheral and thymic CD4+ cells during neonatal infection of BALB/c mice. Despite significant disruptions to the normal adaptive immune response, infected BALB/c mice reproducibly recover from infection, consistent with prior studies on a related virus, mouse thymic virus. In this article, we show that, in contrast to published studies on mouse thymic virus, MRV appears to robustly infect neonatal C57BL/6 (B6) mice, causing severe depletion of thymocytes and peripheral T cells. Moreover, B6 mice recovered from infection. We investigated the mechanism of thymocyte and T cell loss, determining that the major thymocyte subsets were infected with MRV; however, CD4+ and CD4+CD8- T cells showed increased apoptosis during infection. We found that CD8+ T cells populated MRV-infected thymi. These CD8+ T cells expressed markers of activation, had restricted TCR repertoire, and accumulated intracellular effector proteins, consistent with a cytotoxic lymphocyte phenotype and suggesting their involvement in viral clearance. Indeed, absence of CD8+ T cells prevented recovery from MRV infection and led to lethality in infected animals, whereas B cell-deficient mice showed CD4+ T cell loss but recovered from infection without lethality. Thus, these results demonstrate that CD8+ T cells are required for protective immunity against a naturally occurring murine pathogen that infects the thymus and establish a novel infection model for MRV in B6 mice, providing the foundation for detailed future studies on MRV with the availability of innumerable mutant mice on the B6 background.